Four fire engines and 21 firefighters and officers were called to a fire at a caravan in an open yard in Windmill Lane in Stratford.
One caravan was completely damaged by fire. One seven kilogram butane cylinder was cooled to an ambient temperature and removed from the scene.
One man was treated at the scene before being taken to hospital by London Ambulance Service crews.
The Brigade was called at 1511 and the fire was under control at 1641. Fire crews from Stratford, Leytonstone, Plaistow and Poplar fire stations attended the scene.
The cause of the fire is believed to be accidental.